Currently, traditional cut guide designs and instruments are bulky, one-piece components that are expensive to produce. Such traditional cut guides are heavy, cumbersome, non-adjustable in rotation, and have permanently captured cutting slots, which can complicate the surgeon's efforts to properly prepare accurate surgical cuts needed for a successful TKR. Examples of such traditional cut guides are illustrated by the traditional posterior stabilized cruciate notch femoral cut guide 200 shown in FIGS. 11 and 12, and the traditional distal femoral cut guide 3000 depicted in FIG. 25. There is a need for lighter, more efficient and less costly cut guides as disclosed herein. Disclosed herein are instruments, and their methods to manufacture and use, that provide the surgeon with the ability to achieve all of his/her precise preparatory cuts, angular and rotational adjustments, functional checks, and trial confirmation with better designed and less expensive instrumentation.
Femoral trials are instruments that resemble the implanted femoral component and are critical for surgeons to assess and confirm proper restoration of critical outcomes and performance parameters including joint mechanics, range of motion, and soft tissue balance. Like the traditional cut guides, traditional femoral trials are a complex geometry and when provided with traditional methods are expensive and time consuming to produce. The described femoral trial is considerably less expensive to produce, while still satisfying the demanding surgical performance requirements that such an instrument must meet during the procedure.